Highly efficient top-emission organic light-emitting diode on an oxidized aluminum anode

摘要

In today's manufacturing of organic light-emitting diode on silicon for microdisplay technologies, a top-emitting OLED (TEOLED) is required to be fabricated on top of an active-matrix circuitry located on the silicon backplane. This requires a highly reflective anode to enhance the luminance output. However, during the production process of a TEOLED, the hole injection efficiency and electrical conductivity may be suppressed by environmental exposure, in particular, moisture and oxygen. Given this, aluminum is an unfavorable reflective anode due to the primary concern of its native insulating oxide layer. The native oxide tends to grow during the patterning of the metal anode. In this paper, we have discovered that, by utilizing an A1(2)O(3)/MoO3 heterojunction anode structure, a highly efficient device can be made to achieve a current efficiency of 94 cd/A at a luminance of 1000 cd/m(2). X-ray/ultraviolet photoelectron spectroscopy measurements show the formation of molybdenum gap states and favorable energy level alignment for hole injection. Published under license by AIP Publishing.